rqt_moveit: exception occurs upon rospy.has_param (ros1)

[dirk-thomas]

From @130s on April 25, 2013 1:26

rospy.has_param fails to catch an exception that occurs from /usr/lib/python2.7/httplib.py. But since I've only seen so far this issue with very specific situation using rqt_moveit, i'm reporting it as rqt_moveit issue for now.

Stacktrace:

[INFO] [WallTime: 1366848119.366552] PluginContainerWidget; 
Exception in thread Thread-4:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 552, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 505, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/user/catkin_ws/src/rqt_robot_plugins/rqt_moveit/src/rqt_moveit/moveit_widget.py", line 228, in _check_params_alive
    has_param = rospy.has_param(param)
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rospy/client.py", line 536, in has_param
    return param_name in _param_server #MasterProxy does all the magic for us
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rospy/msproxy.py", line 184, in __contains__
    code, msg, value = self.target.hasParam(rospy.names.get_caller_id(), rospy.names.resolve_name(key))
  File "/usr/lib/python2.7/xmlrpclib.py", line 1224, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1578, in __request
    verbose=self.__verbose
  File "/usr/lib/python2.7/xmlrpclib.py", line 1264, in request
    return self.single_request(host, handler, request_body, verbose)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1294, in single_request
    response = h.getresponse(buffering=True)
  File "/usr/lib/python2.7/httplib.py", line 1022, in getresponse
    raise ResponseNotReady()
ResponseNotReady

Reproduction steps:

1. Run Moveit! on PR2 (here I don't describ how to do so)
2. Run rqt_moveit on your machine
3. Once it starts showing the monitored topics, toggle monitor some of the topics, then expand the tree for some of them. Repeat this until you see the error.

has_param throws ROSException, which is handled like this.

rqt_robot_plugins SHA 7604936b849e6e3b2cf5e2d6c3577a04b5964fc2

Copied from original issue: ros-visualization/rqt_robot_plugins#23